Spanish is the official and most spoken language in Costa Rica. All major newspapers and official business are conducted in Spanish. English is used widely in most areas, especially those frequented by tourists, and information for visitors is often bilingual or even exclusively in English. A number of businesses operated by European proprietors can accommodate guests in Spanish, English and their native languages.

Some Costa Rican colloquial expressions:

• Mae or sometimes "Maje" is used akin to the American English word 'dude'. Generally spoken among the male population, or among friends. It is as informal as the word 'dude'. Mae is mostly used by the younger population and Maje by the older population. It is pronounced 'maheh'.
• Pura vida, literally translated as "pure life," is an expression common to Costa Rica. It can be used in several contexts, as an expression of enthusiasm, agreement, or salutation. It's pronounced 'poora veeda'.
• Tuanis, means "OK" or "cool." Was believed to be taken from the English phrase "too nice", but it is actually a word borrowed from the Código Malespín, a code developed for communication during the various Central American civil wars in the 19th century.

A prevalent version of slang in Costa Rica, and other regions of Latin America, is called "pachuco", "pachuquismo" or "costarriqueñismo" and is used by all social classes (to some degree), however, it can be at times vulgar and is considered an informal way of speaking.

For the word "you" (singular informal form), instead of "tú", most people of Cartago use "vos" (as in "vos sos" - you are) which is also common to other American dialects of Spanish (Argentina, Uruguay, Guatemala...), but the word "usted" is prominent in South Pacific Costa Rica and the Central Valley, and preferred over "vos". Either way, formal Spanish is understood and you may use any form of the word "you" you consider proper.

Costa Ricans tend to use the term Regaláme, literally "gift me", instead of "get me". An example is when a Costa Rican says: "regáleme la cuenta", literally "gift me the bill", which is unusual to other Spanish speaking countries, however, it is a very common Costa Rican term. Another such case might be when Costa Ricans go out to buy something, in which case they might use the term this way: "Regáleme un confite y una Coca", literally, "Gift me a piece of candy and a Coke", but it is understood that the person asking is going to buy said things and is not expecting the other to gift him or her those things. A more precise phrase in standard Spanish would be: "Me vende un confite y una Coca", meaning: "Sell me a piece of candy and a Coke".

Limonense Creole (Mekatelyu)

As well as Costa Rican Spanish, there is also an English-based Creole language spoken in Limón Province on the Caribbean Sea coast of Costa Rica. It is called Limonese Creole or Mekatelyu. This Creole language is similar to varieties such as Colón Creole, Miskito Coastal Creole, Belizean Kriol language, and San Andrés and Providencia Creole since all originated from English seafarers and settlers. The name Mekatelyu is a transliteration of the phrase "make I tell you", or in standard English "let me tell you". It is basically English language however it has a very distinctive pronunciation and vocabulary very similar to Jamaican English.